The special stamp uses a washable ink that leaves a transparent, 9-millimeter (0.4-inch) image of an open hand — symbolizing “Stop!” — which can be imprinted on an offender’s hands or belongings.

The mark, however, can only be seen under ultraviolet (UV) light, so the set includes a blacklight that can be used to illuminate it.

The stamp also comes in a small yellow case with a reel cord that can be attached to a visible area — such as bags or pockets — to show that the owner carries it and consequently discourage anyone from groping or committing other forms of harassment.

Yayoi Matsunaga, head of the Chikan Yokushi Katsudo Center (Chikan Prevention Activities Center), said that it was too early to determine the product’s efficiency, but hailed Shachihata for its “very meaningful” move, the Japan Times reported.